Glossary of Pearl Terms D

diffraction: One of the ways nacre layers interfere with light, possibly causing light to split into its component colors (the spectrum), one or more of which can be displayed as overtone and/or orient.

Dobo pearl: An Indonesian Pinctada maxima pearl grown on the Aru Island of Wokam prior to World War II. It is said that 9 mm cultured akoya pearls were used as nuclei.

dolomite nucleus: See Bironite.

Dom?: Trade name for cultured American blister pearl produced with a nucleus that remains in the blister when the shell is cut around the pearl?s perimeter.

drop: A symmetrical pearl shape that?s round on one end and tapers almost to a point on the other. The shape can be short or long and takes its name from a water drop or teardrop.